Angioedema is swelling that happens just below the surface of the skin, most often around the lips and eyes. When you have an allergic reaction, your body produces histamine, which causes blood vessels to swell. Angioedema is like hives, but with hives there are itchy red welts on the surface of your skin. Angioedema is a deeper swelling.

Both hives and angioedema are usually caused by an allergic reaction, to either a food or medication. Things like pollen or insect stings can also cause angioedema. In rare cases, it may be a sign of an underlying condition, such as leukemia or Hodgkin's disease. There are two basic types of angioedema:

• Hereditary angioedema (HAE), a rare condition that is genetic
• Acquired angioedema (AAE)

Angioedema can take anywhere from minutes to hours to develop. It may affect just one side of the body but not the other. In most cases, angioedema is mild. Severe angioedema can cause the throat or tongue to swell, cutting off the airway, and it can be life threatening.

Common symptoms of angioedema include:

• Red welts that suddenly appear, especially near the eyes and lips, but also on the hands, feet, and the inside of the throat
• Burning, painful, swollen areas; sometimes itchy
• Discolored patches or rash on the hands, feet, face, or genitals
• More rarely, hoarseness, tight or swollen throat, breathing trouble
• In a form called angioedema-eosinophilia syndrome, hives, itching, fever, muscle pain, decreased urine, weight gain, and high white blood cell count occur.

Sometimes the cause is unknown. Angioedema may be caused by allergies to foods, dyes, or pollen, or certain medications. Foods that often cause allergies include shellfish, dairy, and nuts. Drugs that often spark allergic reactions include nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen or Advil), blood pressure medications, aspirin, and antibiotics. Conditions such as leukemia, Hodgkin's disease, and connective tissue disorders such as lupus may also trigger angioedema.

These factors increase the risk for angioedema:

• Having hives or angioedema before
• Having a body-wide allergic reaction in the past
• Experiencing injury, sudden temperature change, stress, or anxiety
• Undergoing a dental procedure
• Having ovarian cysts

Your health care provider will do a physical exam and ask about your symptoms. Be sure to tell your health care provider about all medications -- prescription and over-the-counter -- as well as herbs and supplements you are taking. Blood and urine tests may help pinpoint the cause of the angioedema.

Prevention

You should get rid of any known or suspected triggers for allergies. Allergy testing with a trained specialist may help identify what you're allergic to. If you often have angioedema, you should wear a Medic Alert bracelet.

Treatment Plan

If you have mild angioedema, you may be able to treat it with over-the-counter antihistamines or alternative therapies. With severe angioedema, the first priority is to ensure that the person’s airway is open and they can breathe. The next steps include finding and removing the allergen as well as relieving other symptoms. You can manage infrequent attacks as they happen. Frequent attacks may require ongoing treatment, perhaps with an allergist, dermatologist, or other specialist.

Drug Therapies

Several medicines may help prevent or relieve attacks. For mild cases, you can use over-the-counter antihistamines, such as Benadryl, Zyrtec, Allegra, or Claritin. Note that Benadryl often causes drowsiness.

Your doctor may prescribe antihistamines. Mild attacks tend to clear up within 4 days with or without medication. For severe cases, your doctor may prescribe corticosteroids to reduce swelling and itching, or you may need a shot of epinephrine (EpiPen).

Complementary and Alternative Therapies

In a severe attack, you should seek emergency help right away. Do not take any new drugs, herbs, or supplements during an attack.

Following a good nutritional plan and using some herbs in between attacks may help reduce or prevent angioedema. Herbs and supplements may help reduce mild symptoms, especially if you often have angioedema. Find a health care practitioner who is experienced at prescribing herbs and supplements so you can find the right ones for you. It is important to tell your doctor about all medications, herbs, and supplements you are taking.

Nutrition and Supplements

Some foods may trigger angioedema in people who are allergic. You should eliminate any foods or food additives that trigger symptoms. The following are the most common food triggers:

• Seafood
• Nuts
• Legumes
• Eggs
• Chocolate
• Milk
• Berries

Some people may have a reaction in response to:

• Citrus fruits
• Sulfites -- used as an antioxidant or preservative in many foods and beverages
• Yellow dye No. 5 (also called tartrazine) -- those who are allergic to aspirin or other NSAIDs are more likely to have an allergy to yellow dye No. 5

Your health care provider can help identify food triggers by:

• Getting detailed information about your diet
• Doing skin tests for allergies
• Testing suspected triggers
• Watching symptoms as foods are eliminated from your diet, then slowly re-introduced one at a time

If you have stomach symptoms such as abdominal pain, vomiting, diarrhea, or reduced appetite, you may want to try a diet that eliminates common food triggers even if you don't have a specific food allergy.

These supplements may also help treat symptoms:

• Vitamin C may help lower histamine levels, although there isn't a lot of evidence. Reduce dose if diarrhea develops. Vitamin C supplements may interact with other medications, including chemotherapy drugs, estrogen, warfarin (Coumadin), and others.
• Vitamin B12 (by injection) may help reduce the frequency of ongoing attacks, although there isn't a lot of evidence. Doctors don't know whether taking oral B12 would work the same way.
• Quercetin (a plant-based flavonoid) may reduce the likelihood of an allergic reaction, although there isn't a lot of evidence. If you are sensitive to citrus or take calcium-channel blockers to treat high blood pressure, you should avoid quercetin. Quercetin may interact with many other medications, including blood thinners, so ask your doctor before taking it. Very high doses have been associated with kidney damage, so don't take quercetin for more than 2 months without taking a break. Quercetin is best absorbed in its water-soluble form, often referred to as hesperidin methyl chalcone (HMC). It can be harder to find.
• Bromelain is sometimes used to help reduce inflammation. It is often combined with turmeric (Curcuma longa) because it makes the effects of bromelain stronger. People who are allergic to pineapple should not take bromelain. Both bromelain and turmeric may increase the risk of bleeding, especially if you take blood-thinning medication such as aspirin, clopidogrel (Plavix), or warfarin (Coumadin).

Herbs

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, take herbs with care, under the supervision of a health care provider.

• Goldenseal (Hydrastis canadensis) has been used for gastrointestinal symptoms such as stomach pain, diarrhea, and reduced appetite that may go along with a severe allergic reaction. Some health care providers may recommend goldenseal for people with food allergies to prevent or reduce allergic reactions. Goldenseal interacts with a number of medications, including blood thinners and cyclosporine. It may also lower blood sugar. Ask your doctor before taking goldenseal if you take any other medication or if you have diabetes.
• Licorice root (Glycyrrhiza glabra) has been used traditionally to reduce inflammation in the case of an allergic reaction. It may also help support immune system health. Do not take licorice if you have high blood pressure, erectile dysfunction, edema, or heart failure; hormone-sensitive cancers such as breast, prostate, ovarian, or uterine cancer; diabetes; kidney disease; liver disease; or if you are taking corticosteroids prescribed by your doctor. Licorice interacts with a number of medications, so to be safe ask your doctor before taking licorice if you take any other medications.
• Chamomile (Matricaria recutita) has been used traditionally to treat hives, although there is no scientific evidence that it works. Chamomile can make the effects of other sedatives stronger. It also interacts with many other medications. People who are allergic to ragweed should not take chamomile.

Homeopathy

Before prescribing a remedy, homeopaths take into account a person's constitutional type -- your physical, emotional, and psychological makeup. An experienced homeopath assesses all of these factors when determining the most appropriate treatment for each individual.

• Apis is traditionally used for hives and angioedema and may be useful to prevent or treat chronic, recurrent cases.

Acupuncture

Some doctors report that acupuncture may help reduce the frequency or severity of allergic reactions such as angioedema.

If angioedema affects the throat, the person’s airway could be blocked, which could be life-threatening. In rare cases, angioedema may develop into anaphylaxis, which requires emergency medical care to maintain breathing, blood pressure, and heart function and to reverse the reaction.

After an attack, it's important to identify and avoid any triggers and to treat any underlying condition.

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